1.2
Expressions and Equations
July 17, 2025

Shivohm Karogal
3
Min Read
AI Summary
These notes cover understanding and interpreting linear equations both graphically and algebraically, including how to graph proportional relationships and calculate slope. They also explain solving single-variable linear equations by isolating variables and classifying solutions, as well as solving systems of two linear equations through graphing and algebraic methods like substitution and elimination.
Objective
Understand and interpret both linear and graphical equations.
Core Concept
Mastering equations is essential for solving more complex algebraic problems and analyzing relationships between variables.
Graph Proportional Relationships and Interpret Slope
Create a Table:
Miles (X) | Money Earned (Y) |
1 | 10 |
Plot Points on a Graph: Plot each coordinate pair to visualize the relationship.
Calculate the Slope: Use the formula:Slope = Rise / Run
Find the Slope Value: Count vertical change (rise) and horizontal change (run) between two points.
Derive the Linear Equation (y = mx + c)
Find the Slope (m): Use rise/run from two points on the graph.
Identify the Y-Intercept (c): This is where the line crosses the Y-axis.
Form the Equation: Combine both: y = mx + c
Solving Single-Variable Linear Equations
Simplify both sides and combine like terms.
Move variables to one side and constants to the other.
Divide or multiply to isolate the variable.
Classify the solution:
One Solution: Single correct value.
No Solution: Contradictory statement (e.g., 5 = 9).
Infinite Solutions: Both sides match identically.
Solving and Interpreting Systems of Two Linear Equations
Graphically:
Plot both equations on a graph.
The intersection point gives the solution.
Algebraically:
Use substitution or elimination to find the point where both equations are true.